Anisa Mosam

Molecular Characteristics of Human Immunodeficiency Virus Type 1 Subtype C Viruses from KwaZulu-Natal, South Africa: Implications for Vaccine and Antiretroviral Control Strategies

ABSTRACT The KwaZulu-Natal region of South Africa is experiencing an explosive outbreak of human immunodeficiency virus type 1 (HIV-1) subtype C infections. Understanding the genetic diversity of C viruses and the biological consequences of this diversity is important for the design of effective control strategies. We analyzed the protease gene, the first 935 nucleotides of reverse transcriptase, and the C2V5 envelope region of a representative set of 72 treatment-naïve patients from KwaZulu-Natal and correlated the results with amino acid signature and resistance patterns. Phylogenetic analysis revealed multiple clusters or “lineages” of HIV-1 subtype C that segregated with other C viruses from southern Africa. The same pattern was observed for both black and Indian subgroups and for retrospective specimens collected prior to 1990, indicating that multiple sublineages of HIV-1 C have been present in KwaZulu-Natal since the early stages of the epidemic. With the exception of three nonnucleoside reverse transcriptase inhibitor mutations, no primary resistance mutations were identified. Numerous accessory polymorphisms were present in the protease, but none were located at drug-binding or active sites of the enzyme. One frequent polymorphism, I93L, was located near the protease/reverse transcriptase cleavage site. In the envelope, disruption of the glycosylation motif at the beginning of V3 was associated with the presence of an extra protein kinase C phosphorylation site at codon 11. Many polymorphisms were embedded within cytotoxic T lymphocyte or overlapping cytotoxic T-lymphocyte/T-helper epitopes, as defined for subtype B. This work forms a baseline for future studies aimed at understanding the impact of genetic diversity on vaccine efficacy and on natural susceptibility to antiretroviral drugs.

Kaposi's sarcoma-associated herpesvirus-specific immune reconstitution and antiviral effect of combined HAART/chemotherapy in HIV clade C-infected individuals with Kaposi's sarcoma.

Background:Kaposis sarcoma-associated herpesvirus (KSHV) is endemic in South Africa and the clinical manifestation of AIDS-associated Kaposis sarcoma (KS) represents a significant clinical problem. Whereas the positive effects of HAART on the regression of KS have been well established, less is known about the role of herpesvirus-specific cellular immunity in disease improvement. Design:Thirty-three treatment-naive HIV clade C-infected individuals with KS were randomly assigned into two treatment arms (HAART plus systemic chemotherapy versus HAART alone). KSHV-specific cellular immune responses, viral loads and clinical outcome were evaluated. Methods:KSHV, Epstein–Barr virus and HIV-specific cellular immunity was measured using an IFN-γ enzyme-linked immunospot assay in samples obtained at baseline and up to 11 months after treatment initiation. Cell-associated KSHV viremia was determined by real-time polymerase chain reaction. Results:Robust increases in CD4 cell counts and suppressed HIV viral loads were seen in parallel with significant increases in the KSHV-specific cellular immune responses over time. Although slowly increasing after 5 months, KSHV-specific T-cell responses were significantly elevated only after 11 months, with both lytic and latent antigens being more frequently targeted. A trend towards better clinical outcome with HAART plus chemotherapy treatment was observed compared with HAART alone, and was accompanied by a significant reduction in cellular KSHV viral load in the HAART plus chemotherapy-treated subjects but not those treated with HAART alone after 11 months of treatment. Conclusion:The data show a temporal association between the clinical improvement of KS and the re-appearance of KSHV-specific cellular immunity, and demonstrate an effective suppression of KSHV viral replication using combination therapy.

Defining immune reconstitution inflammatory syndrome: evaluation of expert opinion versus 2 case definitions in a South African cohort.

BACKGROUND There is no validated case definition for human immunodeficiency virus-associated immune reconstitution inflammatory syndrome (IRIS). We measured the level of agreement of 2 published case definitions (hereafter referred to as CD1 and CD2) with expert opinion in a prospective cohort of patients who were starting antiretroviral therapy in South Africa. METHODS A total of 498 adult patients were monitored for the first 6 months of antiretroviral therapy. All new or worsening clinical events were reviewed by 2 investigators and classified on the basis of expert opinion, CD1, and CD2. Events were categorized according to whether they were paradoxical or unmasking in presentation. We measured positive, negative, and chance-corrected agreement (kappa) with expert opinion for CD1 and CD2, and reviewed areas of disagreement. RESULTS A total of 620 clinical events were recorded, of which, on the basis of expert opinion, 144 (23.2%) were defined as probable IRIS and 112 (18.1%) were defined as possible IRIS. Of the 144 probable IRIS events, 93 (64.6%) were unmasking in presentation, 99 (68.8%) were associated with dermatological or orogenital disease, and 45 (31.3%) were associated with tuberculosis or major opportunistic infections. Of the 620 clinical events recorded, 41 (6.6%) were classified as IRIS on the basis of CD1, and 156 (25.2%) were classified as IRIS on the basis of CD2. Positive agreement between CD1 and expert opinion was low for both unmasking (17.2%; kappa = 0.24) and paradoxical events (37.3%; kappa = 0.43), mainly because 1 major criterion requires IRIS to be atypical and either an opportunistic infection or a tumor, although negative agreement was >98%. In contrast, CD2 had good positive agreement (>75% for most event types), with a kappa value of 0.75 for paradoxical and 0.62 for unmasking. CONCLUSIONS CD2 agreed well with expert opinion, with additional clinical events, such as arthropathy and inflammatory dermatoses, being classified as IRIS and added to CD2. We propose revised case definitions for both paradoxical and unmasking IRIS.

A randomized controlled trial of highly active antiretroviral therapy versus highly active antiretroviral therapy and chemotherapy in therapy-naive patients with HIV-associated Kaposi sarcoma in South Africa.

Background:The optimal approach to HIV-associated Kaposi sarcoma (HIV-KS) in sub-Saharan Africa is unknown. With large-scale rollout of highly active antiretroviral therapy (HAART) in South Africa, we hypothesized that survival in HIV-KS would improve and administration of chemotherapy in addition to HAART would be feasible and improve KS-specific outcomes. Methods:We conducted a randomized, controlled, open-label trial with intention-to-treat analysis. Treatment-naive patients from King Edward VIII Hospital, Durban, South Africa, a public-sector tertiary referral center, with HIV-KS, but no symptomatic visceral disease or fungating lesions requiring urgent chemotherapy, were randomized to HAART alone or HAART and chemotherapy (CXT). HAART arm received stavudine, lamivudine, and nevirapine (Triomune; CXT arm received Triomune plus bleomycin, doxorubicin, and vincristine every 3 weeks. When bleomycin, doxorubicin, and vincristine were not available, oral etoposide (50–100 mg for 1–21 days of a 28-day cycle) was substituted. Primary outcome was overall KS response using AIDS Clinical Trial Group criteria 12 months after HAART initiation. Secondary comparisons included time to response, progression-free survival, overall survival, adverse events, HIV control, CD4 reconstitution, adherence, and quality of life. Results:Fifty-nine subjects were randomized to HAART and 53 to CXT; 12-month overall KS response was 39% in the HAART arm and 66% in the CXT arm (difference, 27%; 95% confidence interval, 9%–43%; P = 0.005). At 12 months, 77% were alive (no survival difference between arms; P = 0.49), 82% had HIV viral load <50 copies per milliliter without difference between the arms (P = 0.47); CD4 counts and quality-of-life measures improved in all patients. Conclusions:HAART with chemotherapy produced higher overall KS response over 12 months, whereas HAART alone provided similar improvement in survival and select measures of morbidity. In Africa, with high prevalence of HIV and human herpes virus-8 and limited resources, HAART alone provides important benefit in patients with HIV-KS.

Disseminated cutaneous histoplasmosis in patients infected with human immunodeficiency virus

Background: In the pre‐AIDS era disseminated histoplasmosis was rare and the cutaneous manifestations thereof were reported infrequently. A range of unusual clinical manifestations of disseminated cutaneous histoplasmosis (DCH) in AIDS patients has been documented, but the cutaneous histopathological descriptions are short and incomplete. In addition, the histopathological spectrum of AIDS‐associated DCH is poorly recognized.

Kaposi Sarcoma-Associated Herpesvirus (KSHV) Seroprevalence in Population-Based Samples of African Children: Evidence for At Least 2 Patterns of KSHV Transmission

BACKGROUND Kaposi sarcoma-associated herpesvirus (KSHV) infection is endemic among adult populations in Africa. A prevailing view is that childhood transmission is primarily responsible for the high seroprevalence of KSHV among adults that is observed throughout the continent. However, few studies have directly examined children, particularly in locations where KS is not commonly endemic. METHODS Participants were children aged 1.5-8.9 years, including 427 children from a population-based sample in South Africa, 422 from a population-based sample in Uganda, and 567 from a clinic-based sample in Uganda. All serum specimens were tested by the same laboratory for KSHV antibodies with use of 2 enzyme immunoassays (against K8.1 and ORF65) and 1 immunofluorescence assay. RESULTS KSHV seroprevalence was 7.5%-9.0% among South African children and was not associated with age. In contrast, in the Ugandan population-based sample, KSHV seroprevalence increased from 10% among 2-year-old children to 30.6% among 8-year-old children (P(trend) < .001). In the Ugandan clinic-based sample, seroprevalence increased from 9.3% among 2-year-old children to 36.4% among 8-year-old children (P(trend) < .001). CONCLUSION Two distinct relationships between age and KSHV infection among children imply that KSHV transmission among children is not uniform throughout Africa and is therefore not always responsible for the high seroprevalence observed in adults. There are at least 2 patterns of KSHV transmission in Africa.

Immune reconstitution inflammatory syndrome associated with Kaposi sarcoma: higher incidence and mortality in Africa than in the UK.

Objectives:To assess the incidence, predictors, and outcomes of Kaposi sarcoma-associated paradoxical immune reconstitution inflammatory syndrome (KS-IRIS) in antiretroviral therapy (ART)-naive HIV-infected patients with Kaposi sarcoma initiating ART in both well resourced and limited-resourced settings. Design:Pooled analysis of three prospective cohorts of ART-naive HIV-infected patients with Kaposi sarcoma from sub-Saharan Africa (SSA) and one from the UK. Methods:KS-IRIS case definition was standardized across sites. Cox regression and Kaplan–Meier survival analysis were used to identify the incidence and predictors of KS-IRIS and Kaposi sarcoma-associated mortality. Results:Fifty-eight of 417 (13.9%) eligible individuals experienced KS-IRIS with an incidence 2.5 times higher in the African vs. European cohorts (P = 0.001). ART alone as initial Kaposi sarcoma treatment (hazard ratio 2.97, 95% confidence interval (CI) 1.02–8.69); T1 Kaposi sarcoma stage (hazard ratio 2.96, 95% CI 1.26–6.94); and plasma HIV-1 RNA more than 5 log10 copies/ml (hazard ratio 2.14, 95% CI 1.25–3.67) independently predicted KS-IRIS at baseline. Detectable plasma Kaposi sarcoma-associated herpes virus (KSHV) DNA additionally predicted KS-IRIS among the 259 patients with KSHV DNA assessed (hazard ratio 2.98, 95% CI 1.23–7.19). Nineteen KS-IRIS patients died, all in SSA. Kaposi sarcoma mortality was 3.3-fold higher in Africa, and was predicted by KS-IRIS (hazard ratio 19.24, CI 7.62–48.58), lack of chemotherapy (hazard ratio 2.35, 95% CI 1.09–5.05), pre-ART CD4 cell count less than 200 cells/&mgr;l (hazard ratio 2.04, 95% CI 0.99–4.2), and detectable baseline KSHV DNA (hazard ratio 2.12, 95% CI 0.94–4.77). Conclusion:KS-IRIS incidence and mortality are higher in SSA than in the UK. This is largely explained by the more advanced Kaposi sarcoma disease and lower chemotherapy availability. KS-IRIS is a major contributor to Kaposi sarcoma-associated mortality in Africa. Our results support the need to increase awareness on KS-IRIS, encourage earlier presentation, referral and diagnosis of Kaposi sarcoma, and advocate on access to systemic chemotherapy in Africa.

Substantial regional differences in human herpesvirus 8 seroprevalence in sub-Saharan Africa: Insights on the origin of the “Kaposi's sarcoma belt”†‡

Equatorial Africa has among the highest incidences of Kaposis sarcoma (KS) in the world, thus earning the name “KS Belt.” This was the case even before the HIV epidemic. To date, there is no clear evidence that HHV‐8 seroprevalence is higher in this region but interpretation of the available literature is tempered by differences in serologic assays used across studies. We examined representatively sampled ambulatory adults in Uganda, which is in the “KS Belt,” and in Zimbabwe and South Africa which are outside the Belt, for HHV‐8 antibodies. All serologic assays were uniformly performed in the same reference laboratory by the same personnel. In the base‐case serologic algorithm, seropositivity was defined by reactivity in an immunofluorescence assay or in 2 enzyme immunoassays. A total of 2,375 participants were examined. In Uganda, HHV‐8 seroprevalence was high early in adulthood (35.5% by age 21) without significant change thereafter. In contrast, HHV‐8 seroprevalence early in adulthood was lower in Zimbabwe and South Africa (13.7 and 10.8%, respectively) but increased with age. After age adjustment, Ugandans had 3.24‐fold greater odds of being HHV‐8 infected than South Africans (p < 0.001) and 2.22‐fold greater odds than Zimbabweans (p < 0.001). Inferences were unchanged using all other serologic algorithms evaluated. In conclusion, HHV‐8 infection is substantially more common in Uganda than in Zimbabwe and South Africa. These findings help to explain the high KS incidence in the “KS Belt” and underscore the importance of a uniform approach to HHV‐8 antibody testing.

Incidence, clinical spectrum, risk factors and impact of HIV-associated immune reconstitution inflammatory syndrome in South Africa.

Background Immune reconstitution inflammatory syndrome (IRIS) is a widely recognised complication of antiretroviral therapy (ART), but there are still limited data from resource-limited settings. Our objective was to characterize the incidence, clinical spectrum, risk factors and contribution to mortality of IRIS in two urban ART clinics in South Africa. Methods and Findings 498 adults initiating ART in Durban, South Africa were followed prospectively for 24 weeks. IRIS diagnosis was based on consensus expert opinion, and classified by mode of presentation (paradoxical worsening of known opportunistic infection [OI] or unmasking of subclinical disease). 114 patients (22.9%) developed IRIS (36% paradoxical, 64% unmasking). Mucocutaneous conditions accounted for 68% of IRIS events, mainly folliculitis, warts, genital ulcers and herpes zoster. Tuberculosis (TB) accounted for 25% of IRIS events. 18/135 (13.3%) patients with major pre-ART OIs (e.g. TB, cryptococcosis) developed paradoxical IRIS related to the same OI. Risk factors for this type of IRIS were baseline viral load >5.5 vs. <4.5 log10 (adjusted hazard ratio 7.23; 95% confidence interval 1.35–38.76) and ≤30 vs. >30 days of OI treatment prior to ART (2.66; 1.16–6.09). Unmasking IRIS related to major OIs occurred in 25/498 patients (5.0%), and risk factors for this type of IRIS were baseline C-reactive protein ≥25 vs. <25 mg/L (2.77; 1.31–5.85), haemoglobin <10 vs. >12 g/dL (3.36; 1.32–8.52), ≥10% vs. <10% weight loss prior to ART (2.31; 1.05–5.11) and mediastinal lymphadenopathy on pre-ART chest x-ray (9.15; 4.10–20.42). IRIS accounted for 6/25 (24%) deaths, 13/65 (20%) hospitalizations and 10/35 (29%) ART interruptions or discontinuations. Conclusion IRIS occurred in almost one quarter of patients initiating ART, and accounted for one quarter of deaths in the first 6 months. Priority strategies to reduce IRIS-associated morbidity and mortality in ART programmes include earlier ART initiation before onset of advanced immunodeficiency, improved pre-ART screening for TB and cryptococcal infection, optimization of OI therapy prior to ART initiation, more intensive clinical monitoring in initial weeks of ART, and education of health care workers and patients about IRIS.

Kaposi's sarcoma in sub-Saharan Africa: a current perspective.

Purpose of review The aim of this review is to summarize the most recent published literature on HIV/AIDS Kaposis sarcoma in sub-Saharan Africa (SSA). We attempted to update readers on the epidemiology of Kaposis sarcoma herpesvirus infection and HIV Kaposis sarcoma in SSA, as well as clinical features, therapy and immune reconstitution inflammatory syndrome associated with HIV Kaposis sarcoma. Recent findings Seroprevalence rates of Kaposis sarcoma herpesvirus differ across SSA; it is low in South African children as compared to endemic areas like Uganda. The major route of transmission in SSA is horizontal rather than sexual. The incidence of Kaposis sarcoma has increased exponentially with the HIV/AIDS pandemic with a shift in trend demonstrating a dramatic increase in females and occurrence in younger individuals. Kaposis sarcoma specific therapy is underutilized due to poor access to highly active antiretroviral therapy and financial constraints in SSA. As highly active antiretroviral therapy becomes available, clinicians treating HIV/AIDS in SSA need to have a high index of suspicion of Kaposis sarcoma immune reconstitution inflammatory syndrome events. Summary Kaposis sarcoma is a public health concern in SSA. More studies appropriate to therapy for Kaposis sarcoma in resource-poor environments like SSA are imperative. We are hopeful that with the increased availability of highly active antiretroviral therapy, the incidence of HIV Kaposis sarcoma will decrease and management will improve, as it has in the West.